A wide variety of wireless communication techniques have been developed to facilitate wireless telecommunication. Frequency division multiple access (FDMA) refers to a wireless communication technique in which an allocated frequency spectrum is divided into a plurality of smaller frequency cells. Each cell of the allocated spectrum has a carrier signal that can be modulated with data. Dividing the allocated frequency spectrum into cells can increase the amount of data that can be communicated over the spectrum, and also provides an easy mechanism for allocating bandwidth to service providers. For example, specific cells may be allocated to specific service providers, and the wireless network of a given service provider may use one or more allocated cells in order to provide service to its subscribers.
The global system for mobile communications (GSM) standard, standardized by the European Telecommunication Standards Institute (ETSI), is one example of a system that makes use of FDMA techniques. In Europe, for example, frequency bands surrounding 900 megahertz (MHz) and 1800 MHz have been allocated for GSM. The frequency bands surrounding 900 and 1800 MHz are divided by GSM into approximately 548 frequency cells of approximately 200 kilohertz (KHz) per cell. The different cells are allocated to different service providers for use in the service providers' networks. Some cells are used as network beacons to inform subscriber units which cells are associated with a given network, while other cells are used only for delivering network traffic to and from mobile subscriber units. In a GSM network, the different frequency cells also make use of time division multiple access (TDMA), in which time slots are specifically assigned within the cells for time-allocated communication.
One challenge in systems that implement FDMA techniques, such as GSM, is the process of cell selection or acquisition by a subscriber unit. A subscriber unit refers to a device such as a mobile radiotelephone, or the like, which is used by the end user. In an FDMA system, the subscriber unit scans the various cells of the allocated spectrum, looking for the most desirable cell for telecommunication. The most desirable cell is typically a cell associated with the network of the service provider of the subscriber unit, or possibly a cell for which the service provider of the subscriber unit has a good roaming agreement. Cells having higher power signals are also more desirable than lower power cells, e.g., when choosing between cells in the network of a given service provider.